dk.dma.ais.filter

Class ReplayDownSampleFilter

java.lang.Object

dk.dma.ais.filter.ReplayDownSampleFilter

All Implemented Interfaces:

IPacketFilter

@ThreadSafe
public class ReplayDownSampleFilter
extends Object
implements IPacketFilter

A down sampling filter.

For position reports 1,2,3,4 and 18, only one message will be forwarded within the give sampling rate. E.g. one message per minute.

For static reports 5 and 24 the same apply. But it is handled separately from the position reports.

All remaining message types are passed through without down sampling.

As opposed to the DownSampleFilter (which operates on current system time), this filter uses the timestamp on AisPackets as current time when filtering.

Constructor Summary

Constructors

Constructor and Description
ReplayDownSampleFilter() Empty contructor
ReplayDownSampleFilter(long samplingRate) Constructor given sampling rate in seconds

Method Summary

Modifier and Type	Method and Description
protected static int	getMessageId(AisPacket packet) Gets message id.
long	getSamplingRate() Get sampling rate in seconds
boolean	rejectedByFilter(AisPacket packet) Rejected by filter boolean.
void	setSamplingRate(long samplingRate) Set sampling rate in seconds

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReplayDownSampleFilter

public ReplayDownSampleFilter()

Empty contructor

ReplayDownSampleFilter

public ReplayDownSampleFilter(long samplingRate)

Constructor given sampling rate in seconds

Parameters:

samplingRate - the sampling rate

Method Detail

getMessageId

protected static int getMessageId(AisPacket packet)

Gets message id.

Parameters:

packet - the packet

Returns:

the message id

rejectedByFilter

public boolean rejectedByFilter(AisPacket packet)

Description copied from interface: IPacketFilter

Rejected by filter boolean.

Specified by:

rejectedByFilter in interface IPacketFilter

Parameters:

packet - the packet

Returns:

the boolean

getSamplingRate

public long getSamplingRate()

Get sampling rate in seconds

Returns:

sampling rate

setSamplingRate

public void setSamplingRate(long samplingRate)

Set sampling rate in seconds

Parameters:

samplingRate - the sampling rate